Fatal format file error; I'm stymiedmeans that TeX itself can’t understand the format you want. Obviously, this could happen if the format file had got corrupted, but it usually doesn’t. The commonest cause of the message, is that a new binary has been installed in the system: no two TeX binaries on the same machine can understand each other’s formats. So the new version of TeX you have just installed, won’t understand the format generated by the one you installed last year. Resolve the problem by regenerating the format; of course, this depends on which system you are using.
fmtutil --byfmt=<format name>to build only the format that you are interested in.
MiKTeX Options, and in the options window, click
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